Rockwell Automation 8520 9/Series CNC Lathe - Manual (Page 535)

Tool Tip Radius Compensation (TTRC)
Function
Chapter 21
21-51
We recommend that you cancel TTRC by using a G40 command before
any modifications to the current work coordinate system are made,
including any offsets or any change of the coordinate system (G54-G59.3).
If compensation is not cancelled using a G40 command, the control
automatically, temporarily cancels compensation for the change in work
coordinate system. This is done by using the last compensated move in the
current coordinate system as an exit move for compensation.
If compensation was not cancelled by using a G40 command before a
change in the work coordinate system was performed, the control
automatically re-initializes TTRC after the new work coordinate system is
established. This is done by using the first move in the new coordinate
system that is in the compensation plane as a entry move for compensation.
Figure 21.46 gives an example of programming a G92; however, this
would apply to any change in the work coordinate system.
Figure 21.46
TTRC During G92 Offset to Work Coordinate System
Temporary cancel of
compensation here
N10 N11
N12
N14
N15
G41
N13
r
Programmed
path
21.6.7
Changing or Offsetting Work
Coordinate System in TTRC